<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    input {
      outline: none;
    }
  </style>
</head>

<body>
  <input type="text">
  <script>
    /*
    表单获得光标：
    focus 获得焦点
    blur  失去焦点
     */

    const input = document.querySelector('input')
    input.addEventListener('focus', function () {
      console.log(`有焦点触发`)
    })
    input.addEventListener('blur', function () {
      console.log(`失去焦点触发`)
    })
  </script>
</body>

</html>